Limit stop and governor for elevators



Feb. 6, 1923.

C. E; KIMBALL LIMIT STOP AND GOVERNOR FOR ELEVATORS Filed Mar. 21

.. .INVENTOR,

CHARLES E. HJNBAL-L A TT ORNE Y.

Patented Feb. 6, 1923.

UNITED STATES CHARLES E. KIMBALL, OF COUNCIL BLUFFS, IOWA.

LIMIT STOP AND GOVERNOR FOR ELEVATORS.

Application filed March 21, 1921.

To all to 710m t may concern Be it known that I, CHARLES E. KIMBALL,

a citizen of the United States, residing at Council Bluffs, in the county of Pottawat- 5 tamie and State of Iowa, have invented a new and useful Limit Stop and Governor for Elevators, of which the following is a specification.

My invention relates to improvements in limit stops and governors for elevators in which the movements of the elevator car and counter-balancing weights are applied to throw off the current and apply a braking mechanism: and the objects of my improvements are, first, to provide a simplified limit and slack cable control of the operating current and winding machine brake; second, to utilize such limit control for governing any excessive speed oi. the elevator car or weights; third, to so apply such limit stop and regulator to both the weights and the car of an elevator and to greatly simplify the construct-ion of the. class of elevator governors and limit stops.

I attain these objects by the mechanism illustrated in the accompanying drawing, in which Figure l is a diagrammatic illustration of an elevator car, counter-balancing weights, connecting cables, brake drum, and line switch; Fig. 2, is a side elevation of the governor sheave; Fig. 3, is a detailed elevation and cross-section of the governor sheave; Fig. 4, is a diagram of the operation of switch lever; Fig. 5, is a diagram of operation of brake lever.

Similar letters refer to similar parts throughout the several views.

6, is the ordinary cage of an elevator; s, the overhead sheave; a, the counter-balancing weights; 1', and 1", the connecting cables. A sheave c, is suitably suspended by rope or cable e, and over the suspended sheave c, a rope la, passes from a weight n, 45 resting on the cage 1), to a similar weight m,

resting on the counter-balance weights, a.

By means of suitable sheaves, as t and u, the rope or cable, 6, may be carried to any convenient place. The rope or cable 6, engages 50 a part h; the part b, consistsof a movable bar or piece having projections which pro- Serial No. 454,231.

jections on the part, h, engages at 1, a lever 5, holding closed the line switch, 6, and engages at 2, the lever j, of the brake p p on the brake-drum, y; the usual spring f, operates the brake elements, 19 p, upon the brake-drum, y; the lever j, in connection with the link, 7, is adapted against the spring 7', to hold. the brake elements 9 p in an open position or off, when the lever 5, holds the switch 6, closed; the hinged connection of j and 7 are placed off center with the pivot of the link 7 and the lever respectively, in the brake elements p p when the switch is closed and the brake released against the spring, f. The weights, at and m, rest respectively on the cage 6, and the counter-balance weights a. For steadying the motion of the apparatus, the lever 03, hinged to the proper supporting element 9, may be used toprevent undue oscillation of the sheave, c; the usual safety catch may be supplied having the lever 3 on the cage 7), and having the lever 4; on the weights a.

The sheave, 0, when used as a speed governor has two centrifugally disposed weights, to w, each weight held in normal position by springs, 'v o; the weights w and w being adapted by suitable hinging to be centrifugally operated against the springs 12 and o,- a braking means, 00, adapted to move eccentrically with the sheave, 0, has a stop or pin, 2, adapted to engage the weights, 'w and to, when by centrifugal force the weights, w and w are thrown out of their normal position as held by the springs, o and *0, respectively. Upon the weight w or w, engaging the stop or pin, .2, the brake, on, is pressed onto the cable or rope, 7:, over the sheave, c.

When the part It, moves either sufiiciently downward or upward, the levers 5 and j, are released from their engagement with h, at 1 and 2. A suitable rod, 8, with suitable nut, 9, extends slightly beyond the limit of travel of the cage b, and similarly the rod 0, with suitable nut, 10, extends slightly beyond the limit of travel of the counter balanced weights, a. The rod, 8, engages the weight n, and the rod 0, engages the weight m. The rod 8, may be arranged to engage the safety catch lever 3, on the cage 6, and the rod 0,

engages similarly the safety catch lever l, on the counterbalanced weights (t. The; brake-drum y, is attached to the usual winding mechanism for moving the cage Z), up and down the connecting mechanism not here being shown;

The principal part of my invention consists of the use of a weighted cable or rope over a suspended sheave to operate a line switch and elevator brake. When the elevator cage Z), runs beyond its limit of travel the rod 1, will be moved upwards lifting the I weight at, from the cageb the rope or cable 71;, will thus beleiigthened with respect to the distance from the cage b, to the counterbalanced weights at, and due to the pressure of thespring f, on the brake 12,32, the part it, engaging the lever j, will move downwardly astlie sheave c,inoves upw rdly. The movenieiit of the lever j, downward puts the brake p, 1) on and similarly the movement of the lever 5, engagin'g h, at l, moving downward allows line switch ti, to drop open thus the main line, current will be out off and the brake applied to stop the movement of the cage b, connected by the table 7', and the connter-balanced weights a, connected by the ca-blew, Similarly if the cage reaches its highest point the counterbalanced weights a, will reach its limit, the rod 0, will be raised lifting the weight on, from the counterbalance weights at, allowing the sheave c, to

move up vhrdly and the part it, downwardly throwing "out the line switch 6, and throwing the brake p p on. In a similar manner the device is effective as a slack cable stop or governor. Whatever causes a change of relative distance between cage and 'counterweights will move the sheave c, and operate the brake p p, and line switch 6. lnliinit structures of this kind the engagemerit eras part i with the lever ,5, contjro'lling the line switch 5, and the lever 7', controlling the brake 72 p, should be such that it can only be replaced by the operator by going to thebrake lever j, and the switch lever B and, operating the same by hand.

,The limit stop device herein described utilizing thesheave c, may also have coinbinled with it the usualgovernor facilities and safety catches. For this additional. purpose the weightsw and w are provided 'in the sheave 0, held in normal position by the respective spring c t. ,When the cage moves beyond afixed limit of speed by centrifugal force one of the weights as w or c0 will be tlirownout of its normal position held by the springs c .or o, and will engage the stop a wliich will operate the brake :0, clamping the cable or ropeic, to the sheave c. When the rope or cable 7:, is clamped in thesheave 0., the part it, will be thrown upward until the lever. 5, allows the line switch 6, to open and the brake 29 p, to go on,

The holding of the cable is, by the brake a", will also operate the safety catch lever 3. Similarly if the cable should break and the cage 6, descend beyond its limit of speed and likewise the counter-balanced weights a, descend, the cable or rope is, will pull the sheave c, and throw the part 71, upward, throw out the line switch 6, and throw on the brake p p.. The rod 8, will operate the safety. catchlever 3, and the rod 0, will operate the safety catch lever at.

I am aware that prior to my invention centrifugal governors with cables running from the cage over a movable sheave back to the cage have been employed for the operation of safety catches.

But what I claim and desire to secure by Letters Patent, is:

1. The combination ofa move-able sheave; a weighted cable over the same, one end loosely engaging an elevator cage and the other the counter-balance weights of said elevator, and connections from said moveable sheave engaging a line switch and brake.

2. In a limit device for elevators, a moveable sheave, a cable passing over it Weighted at each end, said weights supported respectively on the cage and counter-balanceclweights of the elevator and means for lifting said weights when the elevator cage or counter-balanced weights pass their limit of travel, and connections between said sheave and a line switch and brake.

3. In a limit device and governor for elevators, a moveable sheave; a cable passing over said sheave, weighted at both ends, said weights resting respectively on the cage and counter-balanced weights of the said elevator with means for lifting the said weights when the cage or counter-balanced weights pass their limit of travel; centrifugal weights and a brake on said moveable sheave and connections between said sheave and a line switch and a brake. v v

4-. In a regulating device for elevators; a suspended ,sheave, connections between said sheave, and a line switch of said elevator, an elevator braking mechanism, whereby a vertical movement of said sheave in either direction operates to apply the brake and open the line switch; a weighted cable on said sheave; one weighted end resting on cage of elevator, the other weighted end resting upon the counter-balanced weights; rods engaging said weights and extending beyond the limit of travel of the said cage and counter-balance weights adapted to be moved when said cage or counter-balance weights pass beyond their limit of travel centrifugal weights in said sheave; a brake on said sheave adapted to be operated by the centrifugal motion of said weights and springs position.

5. In a regulating device for an electric elevator; a sheave having centrifugal weights, springs, and a brake adapted to be moved by the operation of the said centrifugal Weights; a cable over said sheave; weights on each end of said cable resting respectively 011 the cage of the elevator and on the counter-balance Weights; rods engaging said Weights; safety catches engaging said rods of said cage and counter-balance Weights and connections between said sheave, the line switch and a brake on said elevator.

CHAS. E. KIMBALL. 

